The present invention relates to an elevator landing door apparatus, and, more particularly, it relates to improvements on the construction of a fire-resistant door for an elevator landing zone.
FIG. 6 and FIG. 7 illustrate a conventional elevator landing door apparatus disclosed in such references as the official gazette on utility model laid open, No. 148685-1988 (Showa 63). In these drawings, the reference number (1) denotes a doorway for the elevator landing, and this doorway (1) is provided with three-side frames (2), and a sill (4) is laid down on the landing zone floor (3) in the above-mentioned doorway (1). The three-side frames (2) mentioned above are comprised of a pair of mutually opposing vertical frames (2a) and an upper frame (2b) suspended horizontally between the upper parts of this pair of vertical frames (2a). Also, a groove (4a) is made in a concave formation in the longitudinal direction on the upper surface of the sill (4) as illustrated in FIG. 7. The reference number (5) indicates a plural number of doors for opening and closing the doorway (1), and this door (5) is provided with a surface plate (6) which has a section approximately in a groove shape and forms a decorated surface, as shown in FIG. 7, vertical reinforcing members (7) having a section approximately in the shape of a hat and welded vertically onto the side of this surface plate (6), namely, the side opposite to the decorated surface, and a back plate (9) covering the opening in the back surface of the surface plate (6) at the side of the elevator shaft (8) and set with a screw in the vertical reinforcing material (7). The reference number (10) indicates a hanger plate which is installed in an upright position in the upper part of the doors (5). On the elevated section of this hanger plate (10), a plural number of rollers (11) are mounted each with a pivot in a such a manner as to o permit their rotating motion, as shown in FIG. 6. The reference number (12) indicates a rail which is mounted horizontally on the wall at the side of the elevator shaft (8) and is thus positioned above the upper frame (2b), and this rail (12) is so arranged that it engages and guides the above-mentioned rollers (11). Then, the reference number (13) indicates a plural number of door shoes fitted out to the lower part of the door (5), and these door shoes (13) are inserted with free play into the above-mentioned groove (4a) in such a manner as to permit their free sliding motion therein and to be guided accordingly.
Therefore, the doors (5) will move smoothly to open and to close the doorway (1), being guided by the rail (12) and the (groove (4a), on the basis of their engagement with the doors (now illustrated) for the elevator cab.
In this regard, the conventional art literature of this kind include the official gazette on utility model laid open, No. 31188-1980 (Showa 55) and No. 29025-1984 (Showa 59), official gazette on patent laid open, No. 75189-1986 (Showa 61), and U.S. Pat. No. 4,282,687 in addition to the official gazette cited above.
Since the conventional apparatus is constructed in the above-described manner such that each door 5 is essentially composed of a surface plate 6, a vertically extending reinforcement member 7 and a back plate 9, there appears a problem that a temperature on the rear surface of the door 5 is undesirably elevated in the event of a fire, whereby instruments in an elevator cage are damaged or, in an extreme case, persons staying in the elevator cage are exposed to serious danger. In practice, a gap between the periphery of the doorway 1 and the doors 5 serves to smoothen the opening/closing of each door 5 (see FIG. 7). However, once a fire takes place, the foregoing gap permits undesirable inflow of smoke from the elevator landing zone into the elevator shaft 8 serving also as a kind of chimney, resulting in damage induced by the fire being enlarged extensively.